I would be concerned with mold (not always visible) at the least, which is very hard to digest and hard on the liver. Even if they were boiled the toxins would still be in them. Rubbery definately means exposed to moisture. I would do everything else but eat them. Sprout in garden, science projects, compost piles, for the animals, etc.
Also, you could try sprouting them, if they don't sprout you know for sure they are compromised.